Hi JacoDrikus is a very serious and competitive Koi keeper, I am sure he wants to further upgrade the quality of his collection. I can assure you he has a few Koi at home that is not for sale. The man has an eye for serious Koi, therefore the quality of the Koi for sale.

Hi-Kui is not contagious and in real terms it has no effect on the overall health of the Koi, as long as the system in which they are kept is of a suitable standard. The main effect of Hi-Kui is cosmetic. It degrades the appearance of your Koi. There is no treatment to cure the surface of the skin on the Koi, as there will always be a mark of coloration be left on the spot where the Hi-Kui was.

You may try this:

Clean the area and dry really well. Scrap the infected area with the back of a scalpel or knife. This will come off just like strawberry jam. It is essential that you remove the entire red grunge. After that clean the area with Hydrogen Peroxide Volume 10, and dry off really good. A hair dryer set on cold will achieve this very well.

You could use a Potassium Permanganate paste, but it could be aggressive if you are going to stand a chance of the red coming back to its former glory. Let the paste dry (use the hair dryer) and cover with friars balsam or

You may freeze the area with lighter gas, and cover it with friars balsam.